Applications of vertically oriented TiO2 micro-pillars array on the electrode of dye-sensitized solar cell

In this research, dye-sensitized solar cells based on TiO2 micro-pillars fabricated by inductive couple plasma etcher were investigated by analyses of X-ray diffraction (XRD), scanning electron microscopy (SEM), contact angle, ultraviolet-visible absorption spectra (UV–vis), and current–voltage characteristics. X-ray diffraction patterns show that the TiO2 anatase phase forms while sintering at 450 °C for 30 min. The SEM images reveal that the diameter and height of TiO2 micro-pillars are about 3 and 0.8 μm, respectively. The measurements of contact angle between TiO2 micro-pillars and deionized water (DI water) reveal that the TiO2 micro-pillars is super-hydrophilic while annealed at 450 °C for 30 min.The absorption spectrum of TiO2 micro-pillars is better than TiO2 thin film and can be widely improved in visible region with N3 dye adsorbed. The results of current–voltage (I–V) characteristics analysis reveal that dye-sensitized solar cell with TiO2 micro-pillars electrode has better I–V characteristics and efficiency than TiO2 film electrodes. This result may be due to the annealed TiO2 micro-pillars applied on the electrode of dye-sensitized solar cell can increase the contact area between TiO2 and dye, resulting in the enhancement of I–V characteristics and efficiency for dye-sensitized solar cell.

Research highlights
► The TiO2 micro-pillars is super-hydrophilic while annealed at 450 °C for 30 min.
► The absorption spectrum of TiO2 micro-pillars is better than TiO2 thin film and can be widely improved in visible region with N3 dye adsorbed.
► The contact area between TiO2 and dye play an important role on the efficiency of dye-sensitized solar cell.